linux-kernel - [PATCH v2 04/15] powerpc/uaccess: Remove __get/put_user

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1e5c895669e8d54a7810b62dc61eb111f33c2c37.1615398265.git.christophe.leroy@csgroup.eu>
Date:   Wed, 10 Mar 2021 17:46:43 +0000 (UTC)
From:   Christophe Leroy <christophe.leroy@...roup.eu>
To:     Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Michael Ellerman <mpe@...erman.id.au>
Cc:     linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH v2 04/15] powerpc/uaccess: Remove __get/put_user_inatomic()

Powerpc is the only architecture having _inatomic variants of
__get_user() and __put_user() accessors. They were introduced
by commit e68c825bb016 ("[POWERPC] Add inatomic versions of __get_user
and __put_user").

Those variants expand to the _nosleep macros instead of expanding
to the _nocheck macros. The only difference between the _nocheck
and the _nosleep macros is the call to might_fault().

Since commit 662bbcb2747c ("mm, sched: Allow uaccess in atomic with
pagefault_disable()"), __get/put_user() can be used in atomic parts
of the code, therefore __get/put_user_inatomic() have become useless.

Remove __get_user_inatomic() and __put_user_inatomic().

Signed-off-by: Christophe Leroy <christophe.leroy@...roup.eu>
---
 arch/powerpc/include/asm/uaccess.h            | 37 -------------------
 .../kernel/hw_breakpoint_constraints.c        |  2 +-
 arch/powerpc/kernel/traps.c                   |  2 +-
 3 files changed, 2 insertions(+), 39 deletions(-)

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index a08c482b1315..01aea0df4dd0 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -53,11 +53,6 @@ static inline bool __access_ok(unsigned long addr, unsigned long size)
 #define __put_user(x, ptr) \
 	__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
 
-#define __get_user_inatomic(x, ptr) \
-	__get_user_nosleep((x), (ptr), sizeof(*(ptr)))
-#define __put_user_inatomic(x, ptr) \
-	__put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
-
 #ifdef CONFIG_PPC64
 
 #define ___get_user_instr(gu_op, dest, ptr)				\
@@ -92,9 +87,6 @@ static inline bool __access_ok(unsigned long addr, unsigned long size)
 #define __get_user_instr(x, ptr) \
 	___get_user_instr(__get_user, x, ptr)
 
-#define __get_user_instr_inatomic(x, ptr) \
-	___get_user_instr(__get_user_inatomic, x, ptr)
-
 extern long __put_user_bad(void);
 
 #define __put_user_size(x, ptr, size, retval)			\
@@ -141,20 +133,6 @@ __pu_failed:							\
 	__pu_err;							\
 })
 
-#define __put_user_nosleep(x, ptr, size)			\
-({								\
-	long __pu_err;						\
-	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
-	__typeof__(*(ptr)) __pu_val = (x);			\
-	__typeof__(size) __pu_size = (size);			\
-								\
-	__chk_user_ptr(__pu_addr);				\
-	__put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \
-								\
-	__pu_err;						\
-})
-
-
 /*
  * We don't tell gcc that we are accessing memory, but this is OK
  * because we do not write to any memory gcc knows about, so there
@@ -320,21 +298,6 @@ do {								\
 	__gu_err;							\
 })
 
-#define __get_user_nosleep(x, ptr, size)			\
-({								\
-	long __gu_err;						\
-	__long_type(*(ptr)) __gu_val;				\
-	__typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
-	__typeof__(size) __gu_size = (size);			\
-								\
-	__chk_user_ptr(__gu_addr);				\
-	__get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \
-	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
-								\
-	__gu_err;						\
-})
-
-
 /* more complex routines */
 
 extern unsigned long __copy_tofrom_user(void __user *to,
diff --git a/arch/powerpc/kernel/hw_breakpoint_constraints.c b/arch/powerpc/kernel/hw_breakpoint_constraints.c
index 867ee4aa026a..675d1f66ab72 100644
--- a/arch/powerpc/kernel/hw_breakpoint_constraints.c
+++ b/arch/powerpc/kernel/hw_breakpoint_constraints.c
@@ -141,7 +141,7 @@ void wp_get_instr_detail(struct pt_regs *regs, struct ppc_inst *instr,
 {
 	struct instruction_op op;
 
-	if (__get_user_instr_inatomic(*instr, (void __user *)regs->nip))
+	if (__get_user_instr(*instr, (void __user *)regs->nip))
 		return;
 
 	analyse_instr(&op, regs, *instr);
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 1583fd1c6010..1fa36bd08efe 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -864,7 +864,7 @@ static void p9_hmi_special_emu(struct pt_regs *regs)
 	unsigned long ea, msr, msr_mask;
 	bool swap;
 
-	if (__get_user_inatomic(instr, (unsigned int __user *)regs->nip))
+	if (__get_user(instr, (unsigned int __user *)regs->nip))
 		return;
 
 	/*
-- 
2.25.0